training started at 6:00 this morning in more than a dozen cities. crews practiced ron -- repelling. other exercises include a mock plane hairjacking and chemical sabotage. the training helps officers gain individual tactical skills and helps departments coordinate resourcesle the xerosizes are going on across the nation as part of home lean security training. >> a new law enforcement tool in alameda county is raising fears of big brother. the tool is this drone. weighs less than four pounds, has an hd camera and flies at 400 pete above ground. the drone will be used to follow criminals of the run but critics have their doubts, even if it's cheaper than a helicopter. >> helicopter, two to three million dollars with four to six hundred dollars an hour in flight costs. the system, $40,000. >> we absolutely need nor mftion. >> drones are subject to tremendous potential abuse, given the wealth of information they can collect. we risk proceeding into a complete surveillance state. >> ama: the aclu is concerned residents' privacy will be my prey miced and